The invention relates to the manufacture of fluid tight joints in metal tubing for heat exchangers such as condensers and evaporators use in air conditioning and refrigeration systems. Traditionally, in fabricating aluminum heat exchangers, most of the joints are soldered at one time as by dipping the entire assembly in an ultrasonic solder bath. In employing this method of soldering joints the heat exchangers are turned so that the joints and particularly the return bends to be soldered end up on the bottom of the heat exchangers.
One problem with orienting the heat exchangers for soldering has been that of ensuring that the assembled parts to be soldered do not move relative to each other to the dip soldering operation and the completion of the joint. One attempt at solving this problem has been as shown in U.S. Pat. No. 3,833,986-DeCicco and U.S. Pat. No. 3,957,289-Kilgore et al to provide the male portion of the joint with a plurality of spaced projections or nibs which frictionally engage the inner wall of the female portion of the joint. This system has proven adequate when employed in return bends wherein both ends of the return bend are frictionally held against movement.
However, some difficulties have been encountered when a more complex section of tubing is to be soldered to the heat exchanger, as for example components that require only one end to be attached to the heat exchanger. In many of these instances, when a number is supported at only one of its ends, movement occurs between the memers to be soldered that ultimately results in joints that are not adequately sealed. One system employed is to use fixtures to hold these members while they are being soldered. This has solved the problem but is obviously costly in that special fixtures must be provided for the design configuration of each particular member, and time consuming in that the fixtures must be secured to the member and removed after each soldering operation.
Accordingly, one object of the instant method is to provide a method wherein the members to be joined to the heat exchanger at only one end of their ends are effectively held together in their designed position without the use of externally applied members that are not part of the heat exchanger or refrigeration system.